Controls for outrigger assemblies of mobile cranes and the like



O Umted States Patent 11 13,550,506

I72] lnventor Eugene C. Gardenhour [56] References Cited Waynesbow.UNITED STATES PATENTS {21) P M 823439 2,643,515 6/l953 Harsch 91/414xi221 PM 1969 2,861,606 ll/l958 Fish 91/414x I451 Patented 3 354 78911/1967 Schenkelberger 60/E [73] Assignee Grove Manufacturing CompanyShady Grove, Pa. Primary Examiner-Edgar W. Geoghegan a corporation ofPennsylvania Al 10f y- Y & Gates [54] CONTROLS FOR OUTRIGGER ASSEMBLIES0F S S THE LIKE ABSTRACT: Simplified controls for the forward and rearalms rawmg outrigger assemblies of mobile cranes or like machines com-[52] US. Cl 91/414, prise a single control valve having only threepositions to ena- 2 l 2/145 ble the crane operator to readily conditionthe fluid circuit for [51 Int. Cl FlSb 9/17, extension or retraction ofthe several cylinders of the outrigger B66c 23/80 assemblies. Coactingelectrical controls permit rapid, selective [50] Field of Search 91/414;operation of the several cylinders in any desired sequence 60/E, 97L; 2l 2/ l 45 from a pushbutton console CONTROLS FOR OUTRIGGER ASSEMBLIES OFMOBILE CRANES AND THE LIKE BACKGROUND OF THE INVENTION There is anincreasing need for more simplified controls for large mobile craneswhich are becoming so widely used in building construction and otherfields. The crane operator has a very demanding job and one whichrequires skill and close attention in the interest of safety andprevention of property damage. The crane operator's cab is compact andat best the operator must give attention to a rather large number ofcontrol elements and consequently any substantial simplification ofcontrols is of great importance in the overall efficiency of operationof the crane and in furthering safety and economy.

Conventionally, the fluid pressure operated outrigger assemblies ofmotorized cranes involve eight separate power cylinder units, four eachfor the front and rear assemblies. It has been customary to provide anindependent control valve and control valve lever for the operation ofthese cylinder units resulting inevitably in crowding the craneoperator's cab and control console.

The objective of this invention is to improve upon and simplify theprior art arrangement for controlling the cylinders of the front andrear outrigger assemblies. This is achieved in the invention by theprovision of a single three-position four-way valve which is operablethrough a single lever to condition the fluid control circuitselectively for extending or retracting the cylinders of the front andrear outrigger assemblies. A neutral valve position is also provided.Associated with the single three-position control valve is a compactpushbutton switch console to be used by the crane operator for quicklyand conveniently extending or retracting the several cylinders of theoutrigger assemblies in any desired sequence, once the single controlvalve is set for extension or retraction. The pushbutton switches areelectrically connected with stacks of normallyclosed solenoid-operatedtwo-way valves individual to the power cylinder units of the front andrear outrigger assemblies. When these solenoid operated valves areclosed, the cylinders of the outrigger assemblies are locked and whenthe valves are opened electrically, the several cylinders will extend orretract depending upon the setting of the single or master controlvalve.

Other features and advantages of the invention will be apparent to thoseskilled in the art during the course of the following description.

BRIEF DESCRIPTION OF DRAWING FIGURES FIG. 1 is a fragmentary explodedperspective view of a mobile crane including outrigger assembliesequipped with the controls of the invention.

FIG. 2 is a schematic view of the electrical-fluid control system.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings indetail wherein like numerals designate like parts throughout the same,the numeral in FIG. 1 shows a portion of the wheeled carrier ormotorized chassis for a hydraulic crane or like machine to the which theinvention is applicable. As shown, the carrier includes sturdylongitudinal main frame members-ll. the rear wheels only of the carrierbeing shown in broken lines. Immediately rearwardly of and some distanceforwardly of the carrier rear wheels are rear and forward outriggerassemblies 12 and 13 whose mechanical construction is conventional andneeds to be described only briefly for a proper understanding of theinvention which resides in simplified controls for the several powercylinder units of these outrigger assemblies.

As shown, each outrigger assembly 12 and 13 comprises a pair oftransverse opposed side-by-side extensible and retractable fluidpressure operated cylinders 14 and 15. each having a housing securelybracketed to the carrier main frame. These cylinders 14 and 15 arecommonly termed the leftand right-hand side extension cylinders of theoutrigger assemblies.

The rear and forward outrigger assemblies further comprise leftandright-hand vertical stabilizer cylinders 16 and 17 having housings whichare firmly anchored to the extensible and retractable components of thecylinders 14 and 15 and bodily carried thereby. so that the verticalstabilizer cylinders will be moved laterally outwardly and inwardlyrelative to the wheeled carrier main frame at proper times. Thestabilizer cylinders 16 and 17 are equipped at the lower ends oftheirextension elements with stabilizing pads or feet I8. conventionallyconstructed. Therefore, each outrigger assembly 12 and 13 consists ofone pair of opposed horizontal transverse extension cylinders and onepair of coacting vertical stabilizer cylinders and the purpose of theoutrigger assemblies in stabilizing the crane during lifting operationsis well known.

Referring to FIG. 1, the crane operator's cab is shown as an integralpart of the turntable structure 20 which carries an extensible craneboom 21 or the like. The turntable structure in cludes a bull gear 22,suitably journaled on the wheeled carrier as at 23 and turned in aconventional manner by a power drive, not shown.

The electrical-fluid control means for the outrigger assemblies 12 andI3 is shown schematically in FIG. 2 and certain components thereof areshown in FIG. 1. as will be described, This control means comprises asingle manually-operated three-position four-way fluid control valve 24of the spool type which is spring-loaded by springs 25 and 26 to anormal neutral position, FIG. 2. Associated with this master controlvalve 24 is a pushbutton switch console 27 located with the valve 24 inthe crane operators cab, FIG. 1. Associated with the front and rearbanks 28 and 29 of the pushbutton switches on console 27 are acorresponding number of normally-closed two-way spool valves 30, eachhaving an operating solenoid 31, as shown. Referring to FIG. 2, thesolenoid operated valves 30 are individual to the several cylinders 14,15, I6 and I7 of the front and rear outrigger assemblies 13 and 12. Thephysical arrangement of the valves 30 in two groups adjacent theoutrigger assemblies is depicted in FIG. 1, although the preciselocation of the valves is not critical.

Referring in greater detail to FIG. 2, the fluid control system embodiesa suitable source or reservoir 32 supplying a pump 33 through a line 34.An output line 35 from the pump has a check valve 36 immediatelyupstream from three-position valve 24, the latter being shown in abalanced or neutral position to allow continuous circulation of fluidthrough a neutral or bypass line 37 having a connection at 38 with theoutput line 35 and having a second connection at 39 with a fluid returnline 40 leading back to the reservoir 32.

A further fluid supply line 41, leading downstream from the valve 24,passes through a conventional turntable swivel 42 shown in broken linesin FIG. 2 and having a connection at 43 with a lateral supply line 44,common to branch lines 45, 46, 47 and 48 leading to ports of thenormally-closed two-way solenoid operated valves 30, as shown. Thevalves 30 are held closed by suitable springs 49. The other ports ofvalves 30 connect with downstream hoses or lines 50, 5 1, 52 and 53,feeding the piston ends of the respective cylinders l6, 14, 15 and 17 ofthe forward outrigger assembly 13. The rod ends of these same cylinderunits are connected with additional fluid lines 54, 55, 56 and 57, allleading to a common manifold 58 having an outlet line 59 connected at 60to another line 61 leading back to the swivel 42 and through the same ina conventional manner and, finally, leading back to the return ports ofthree-position valve 24 and to the return line 40.

In a similar manner, a supply line 44' leads from the connection 43 tosupply the several branch lines 62, 63, 64 and 65 of the two-waysolenoid operated valves 30 of rear outrigger assembly 12. These valves30 are also held closed by the aforementioned springs 49. The valves 30of assembly 12 are connected with downstream lines 66, 67, 68 and 69leading to the piston ends of the respective cylinders 16, I4, 15 andI7. The rod ends of these cylinders are connected through lines 70, 71,72 and 73 with a common manifold 74 having an outlet line 75 leading tothe connection 60 and return line 61.

lt'may be seen that the console 27 has a separate and independent pushbutton switch 76 for each of the eight solenoids 31 which serve atproper times to open the valves 30. The switches in the two banks 28 and29 are connected through cables 77 and 78 with the respective wires 79,80, 81 and 82 leading to the solenoids for the front assembly 13 and tosimilar wires 83, 84, 85 and 86 extending to the coils of thecorresponding solenoids 31 of rear outrigger assembly 12. FIG. 2 alsoshows the usual ignition switch 87 of the motorized crane carrier aheadof the several switches 76 and being connected with a conventionalcurrent source 88 on the carrier. It should also be mentioned that thetwo cables 77 and 78 also have conventional connections with theturntable swivel 42, the details of which are not important to a properunderstanding of the invention.

OPERATION The simplified control system for the outrigger assembliesoperates in the following manner. Assuming the master control valve 24to be in the neutral position shown in FIG. 2, and with the pump 33operating. the working fluid simply circulates continuously from thereservoir 32 through the pump and through the neutral ports of the valve24 and back to the return line 40 at the connection 39, as indicatedThere will thus be no pressurizing of the supply line 41 or of any ofthe branch lines leading to or from the several cylinder units of thetwo outrigger assemblies. Under these conditions, if the operator closesany of the pushbutton switches 76 and thereby opens thesolenoid'operated valves 30, there will be no movement of the cylinderunits.

Assuming further that all of the cylinders of the two assemblies l2 and13 are retracted as shown in the drawings, and the ignition switch 87 isclosed and it is desired to extend or activate the outrigger assemblies,the following operations are performed by the crane operator. Thethree-position valve 24 has its spool shifted to the left in FIG. 2,compressing the spring and thereby aligning the right-hand or extendports with the lines 3541 and 40-61. As shown by the flow indicatorarrows 89, working fluid from the pump 33 will now flow by the checkvalve 36 and through the valve 24 to the line 41 and connection 43. Fromthis connection, fluid will flow simultaneously through the lines 44,45, 46, 47 and 48 to the inlet ports of the now-closed valves of theforward assembly 13. Simultaneously, fluid is delivered through the line44' and the lines 62, 63, 64 and 65 to the inlet ports of the now-closedtwo-way valves 30 of rear outrigger assembly 12. As long as the valves30 of the two assemblies remain closed, no fluid is admitted to thepiston ends of the several outrigger cylinders of the two assemblies andthe pistons all remain retracted, as shown. The operator, by closing thepushbutton switches 76 of the two banks in the proper order which willbe visibly indicated on the face of the console 27, will causeenergizing of the solenoids 31 of the center pair of valves 30 for eachassembly 12 and 13 and these valves will open and admit working fluidthrough the lines 51 and 52 and 67 and 68 to the piston ends ofextension cylinders 14 and 15 of the two assemblies Y12 and 13. Thisproduces immediate lateral extension of the two outrigger assemblieswhile their vertical stabilizer cylinders are still retracted from theground.

The fluid displaced by movement of the pistons outwardly in the pairs ofcylinders 14 and 15 will pass through the lines 54 and 55 and 70 and 71to manifolds 58 and 74 and from these manifolds through lines 59 and 75to the return line 61 leading back through the valve 24 and return line40 to complete the fluid circuit.

Similarly, the operator now depresses and closes the remainingpushbutton switches on the console 27 and in so doing energizes theoutboard pair of solenoids 31 in each outrigger assembly and opens theassociated normally-closed valves 30 and admits fluid through the lines50 and 53 and 66 and 69 to the piston ends of cylinders 16 and 17 of thetwo outrigger assemblies. This immediately'causes downward extension ofthe two stabilizer cylinders of each assembly so that the pads 18 willengage the ground or suitable shoring placed beneath the pads. When thistakes place. fluid is displaced from the rod ends of cylinders 16 and 17through lines 56 and 57 and 72 and 73 to manifolds 58 and 74. and fromthese manifolds to lines 59 and 75 and return lines 61 and 40, aspreviously described.

When it is desired to retract the two outrigger assemblies to theirpositions as shown in FIG. 1, the following sequence takes place. Theoperator moves the three-position spool valve 24 to the right againstthe force of spring 26 and thereby aligns the left-hand or retract"valve ports with the respective lines 3541 and 40**61, the direction offlow through the valve 24 being indicated by the flow arrows 90. Thiscauses the pump 33 to deliver fluid through the line 35 and check valve36 and through the control valve 24 to the line 61 and from this linethrough the branch lines 59 and 75 to manifolds 58 and 74. and fromthese manifolds to the several lines connecting with the rod ends of thefour cylinder units .embodied in the assemblies 12 and 13. At this time.all of the valves 30 are closed and all of the assembly cylinders willstill be locked in their extended positions.

The crane operator will now close the pushbutton switches 76 associatedwith the outboard pair of valves 30 of each outrigger assembly toimmediately open these valves and when this occurs, the rightandleft-hand stabilizing cylinders 16 and 17 of each outrigger assembly canretract to the positions shown in the drawings and the displaced fluidwill pass through lines 50 and-53 and 66 and 69 to the now open outboardpairs of valves 30 and from these valves through the lines 45 and-48 and62 and 65 into the lines 44-and 44' and the line 41 and through thevalve 24 back to the return line 40 and reservoir. 7

With the vertical stabilizer cylinders retracted, the operator will nowclose the remainingpushbutton switches 76 to cause opening of theinboard pairs of valves 30 in the two assemblies 12 and 13 and this willin turn allow the pistons of extension cylinders 14 and 15 of the twoassemblies to retract. The fluid displaced by. this last retraction willflow through lines 51 and 52 and 67 and 68 and through .the associatedvalves 30 to lines 46 and 47 and 63 and 64 and then through lines 44 and44 and line 41 and through the valve 24 back to the return line 40because of the flow path arrangementin the three-position valve shown at90. At this time, all cylinders of the rear and front outriggerassemblies 12 and 13 have been returned to their positions shown in thedrawingsand, if desired, the threeway valve 24 may be released to theneutral position of FIG. 2

- where it is held in valance by the opposing springs the opposing and26.-

It may now be seen that the crane operator needs only to make two simpleadjustment of the spool valve 24to the extend" and retract" positions,followed by the closing of the pushbutton switches on the console 27 inthe proper order to extend and retract the several cylinders of thefront and rear outrigger assemblies in the desired sequence. As stated,all of the 'valves '30 are normally closed and open when the associatedpushbuttonswitch is closed bythe operator depressing it. T he switchesthemselves are normally open I crane or the like, said outriggerapparatus including at least a pair of horizontally extensible andretractable cylinders and at least a pair of vertically extensible andretractable cylinders, said control system comprising in combinationwith said cylinders a single multiposition working fluid control valvehaving use positions to supply working fluid to all of said cylinders tocause extension and retraction thereof, an electrical switch consolenear said control valve having switches individual to said cylinders foroperating the cylinders in a desired sequence, and electrically-operatednormally-closed valves intervened between said cylinders and switcheswith one nor mally-closed valve in a fluid circuit with one of saidcylinders and said control valve, there being a separate electricalconnection between one of said switches and the associatednormally-closed electrically-operated valve.

2. The structure of claim 1, and wherein said control valve is athree-position four-way valve including a neutral position and extendand retract positions, said three-position valve when in the extendposition delivering working fluid to piston ends of said cylinders andsaid control valve when in the retract position delivering working fluidto the rod ends of said cylinders, and said electrically-operated valvesprior to opening maintaining said cylinders locked irrespective of theadjusted position of said control valve.

3. The structure of claim 1, and said outrigger apparatus comprising aforward and a rear outrigger assembly each having a pair of opposedextension cylinders and a pair of stabilizer cylinders carried by themovable elements of the extension cylinders, said switches andelectrically-operated valves corresponding in number to the cylinders ofthe forward and rear assemblies and being disposed in coacting groupswith the cylinders of each assembly, electrical circuit meansinterconnecting the switches and electrically-operated valves in saidgroups, and fluid circuit means interconnecting the cylinders of eachoutrigger assembly with one group of electricallyoperated valves andwith said single multiposition control valve.

4. The structure of claim 3, and said fluid circuit means including amanifold common to the cylinders of each assembly, and a fluid lineleading from each manifold to said single multiposition control valve.

5. The structure of claim 4, and fluid conduits leading from themanifold of each assembly to the piston rod ends of the cylinders ofsuch assembly, and additional fluid conduits leading from the pistonends of the cylinders of each assembly to the normally-closedelectrically-operated valves of each assembly.

6. The structure of claim 1, and said switches on the console beingnormally open manually operable switches, and said normally closedvalves being solenoid operated valves, and conductors electricallyinterconnecting said switches with the coils of said normally-closedvalves.

7. A control system for a crane outrigger apparatus having lateralextension cylinders andsubstantially vertical stabilizer cylinders, saidcontrol system comprising a single plural-position selector valve means,fluid conduit means interconnecting said selector valve means with thecylinders of said outrigger apparatus. and coacting fluid circuitenergizing means connected with the cylinders of the outriggersapparatus including normally-closed valves individual to the cylindersof said apparatus and normally blocking the flow of fluid toward or awayfrom said cylinders.

8. The structure ofclaim 7, and said energizing means comprising anenergizing switch for each cylinder of said apparatus and electricaloperators for the normally-closed valves and being electricallyconnected with said switches.

9. The structure of claim 7. and said electrical operators comprisingsolenoids for causing opening of the normallyclosed valves when thesolenoids are energized by closing said switches.

10. The structure of claim 7, and said selector valve means being athree-position selector valve having a neutral position and positions tosupply working fluid to said outrigger apparatus cylinders in properflow direction to selectively extend and retract the cylinders, and saidfluid circuit energizing means including manual selector elementsindividual to said cylinders and to said normally-closed valves andoperable to open the normally-closed valves in a desired sequence.

11. The structure of claim 10, and said selector elements compriseselector switches and said normally-closed valves are solenoid-operatedvalves having coils electrically connected with said switches.

